Articles formed of (meth)acrylic resin compositions have excellent transparency and low optical distortion, and therefore find wide application as an optical component such as lenses, prisms, retardation films, light guide plates, light diffuser films, protective films for polarizer plates and the like.
As a method for producing a (meth)acrylic resin composition, Patent Document 1, for example, discloses a method comprising subjecting a monomer mixture predominantly comprising methyl methacrylate to continuous bulk polymerization in a single complete mixing-type tank reactor using no solvent, in which the polymerization is carried out after the content of oxygen dissolved in the monomer mixture is regulated to not more than 1 ppm by inert gas introduction, with the use of a radical initiator having a half life of 0.5 to 120 seconds at the polymerization temperature, while stirring with a stirrer having agitation power consumption of 0.5 to 20 kW per 1 m3 of the reaction mixture, with the mean residence time being set in away that the ratio of the half life of the radical initiator to the mean residence time at the polymerization temperature is 1/200 to 1/10000, and at conversion from a monomer of 45 to 70% at 130 to 160° C.
Patent Document 2 discloses a continuous polymerization apparatus and a method of continuous polymerization using the continuous polymerization apparatus, for continuous and steady production of an acrylic resin composition, the apparatus having a means for controlling the feeding amounts of a starting monomer and/or a polymerization initiator so that the temperature within a reaction tank is maintained to be equal to the temperature of a temperature regulator that regulates the temperature of the interior wall surface of the reaction tank.